Vat dyestuffs and their leuco esters



Patented Jan. 9, 1940 UNITED STATES,

PATENT. OFFICE I 2,186,389 vA'r DYESTUFFS AND THEIR LEUCO ESTERS Heinrich Neresheimer,

Ludwigshafenon-the- Ithine, Ernst Honold,Frankfort-on-the-Main, Berthold Stein, Ludwigshafen-on-the-Rhine, Max Schubert, Frankfort-on-the-Main, and

' Ernst Anton,

Ludwigshafenon-the-Rhine,

Germany, assignors to General Aniline Works, Inc., New York, N.'Y., a corporation of Delaware I No Drawing. Application August 30, 1938, Serial No. 227,526. In Germany September 2, 1937 8 Claims. (01'. 260-192) group in the aryl radicle with'oxidizingagents.v

The aryl radicle may be, for example, a'radicle of the benzene, naphthalene or diphenyl series.

The treatment may be carried out in an acid medium, as for example with chromic acid or chromates, or also in an alkaline or neutral liquid,

as for example with aqueous alkali hypochlorite or bromite solutions. Nitrous acid or substances yielding the same are unsuitable for the oxidation 15 because diazotizationtakes place.

The aminoarylanthraquinones.may also contain any other atoms or groups and also attached rings, as ior example pyridine rings. The expression Y anthraquinone. series therefore in- 3 cludes in general compounds containing the characteristic part of anthraquinone but which-may also contain any rings in the alpha-beta or betabeta positions. I

' The new dyestuffs are distinguished byhigh fastness, in particular by an excellent fastness to light. Their solutionsin sulphuric acid have a deeper coloration than those of the initial materials. They are usually soluble with difficulty in 7 organic solvents. g

9 The said vat dyestuffs may also be obtained by starting, insteadof from aryl derivatives containing an amino group on the aryl radicle, from aryl derivatives of the anthraquinone series containing the nitrogen on the aryl radicle in a lower stage of oxidation than'in the azo linkage and oxidizing the same, or by starting from aryl derivatives of the anthraquinone series containing nitrogen in the aryl radicle in a higher stage of oxidation than in the azo linkage and then re- 40 ducing tothe corresponding azo compounds, or by treating azoaryl-aroylbenzoic acids with condensing agents, or by oxidizing dianthrylazo hydrocarbons of the aryl series which have on the mscarbon atoms of the anthryl groups a lower stage 45 of oxidation than anthra'quinonyl. a

As oxidizing agents for aryl derivatives of the anthraquinone series which contain nitrogen in the aryl radicle in a lower stage of oxidation than in the azo linkage, as forexample for the 50 oxidation of aryl derivatives containing hydrazo groups, there may be mentioned for example chromic acid, manganic acid,-permanganic acid, hypochlorous acid and hypobromous acid. They may be allowed to act in acid, neutral or alkaline 55 media. The oxidation may also be effected intramolecularly. In this way there is obtained from the hydrazo compound by 'dispr'oportionation the azo compound and also the aminoaryl compound.

For the reduction of aryl derivatives of the anthraquinone series which contain nitrogen in the aryl radicle in a higher stage of, oxidation than the azo linkage, for example for the'redu'ction of anitro, nitroso, diazo or. azoxy group, there may be used for example alkali sulphides, stannous chloride or dextrose in alkaline solution,

For the conversion of azoarylaroylbenzoic. acids into the vat dyestuffs theremay be used for ex- ,or also ammoniacal cuprous oxide solution or sulample sulphuric acid, phosphoric acid, zinc chloride or alkyl sulphuric acids. I v

The dianthrylazo hydrocarbons of the .aryl series which have on the ms-carbon atoms of the anthrylgroup alower stage of oxidation than anthraquinonyl may be oxidized in neutral, alka line or acid media depending on the stage of oxidation of the initial material. Thus for example chrom-ic acid in acid medium may be used for the oxidation of the anthracene stage, and

for the oxidation of the anthrahydroquinone stage, which may also be present in the form of an ether or ester, there may be used nitrous acid, .chromicacid, iron chloride, hypohalites and the like.; Esters of the anthrahydroquinone stage may also be oxidized on the fibers. to the vat dyestuffs. a

lBy treating the dyestuffs in the presence of a tertiary base with metals and derivatives of sul- "phuric acid having an esterifying action,.they

may be converted into leuco sulphuric esters. The said leuco sulphuric esters thus obtainable crystallizein the form of thealkali salts or their salts with organic bases in an excellent manner and have good solubility in water; They have an excellent affinity for fibers and yield very powerful dyeings of excellent fastness by development in, the usual manner.

than in the azo linkage by oxidation, or leuco sul. .phuric acid esters of aryl derivatives of compounds of theanthraquinoneseries which contain the nitrogen on the aryl radicle in a higher stage of oxidation than in the 2.2;) linkage by reduction, I

' into leuco-tetrasulphurio acid esters of the corre-,

sponding azo compounds.

As oxidizing agents for the conversion of leuco sulphuric acid esters of derivatives of arylanthraquinones containing the nitrogen in the aryl radicle in a lower stage of oxidation than in the azo linkage, as for example for the oxidation of an amino or hydrazo group present on the aryl radicle, there may be mentioned in particular hy' pohalites, alkali ferricyanides and peroxides.

For the reduction of leuco sulphuric acid esters of aryl derivatives of compounds of the anthraquinone series which contain the nitrogen in the aryl radicle in a higher stage of oxidation than in the azo linkage, as for example for the reduction of a nitro, diazo or azoxy group attached to the aryl radicle, there may be used for example alkali sulphides, stannous chloride or dextrose in alkaline solution or also ammoniacal cuprous oxide or alkali sulphites depending on the nature Y of the initial materials.

The following examples will further illustrate how the said invention maybe carried out in practice but the invention is not restricted to these examples. The parts are by weight.

' Example 1 60 parts of 4amino-2-phenylanthraquinone are dissolved in 3000 parts of hot glacial acetic acid; a solution of 20 parts of chromic acid in 20 parts of water is then allowed to drop in. There separates, with boiling, a green-yellow compound which becomes paler upon further heating. After 15 minutes the dyestuif is filtered oil by suction while hot and Washed with glacial acetic acid and water. By crystallization from a large amount of nitrobenzene, large yellowv needles are obtained which dissolve in sulphuric acid giving a bluish red coloration.

The new dyestuff yields powerful yellow dyeings of very good fastness on cotton from a yellow-redvat. According to analysis and its prop-- erties, the azo compound corresponding to the amino compound used is present.

Example 2 A solution of 45 parts of sodium bichromate in 25 parts of Water is added in the manner described in Example 1 to a solution of 30 parts of 4-amino-2-phenylanthraquinone in 1000 parts of boiling glacial acetic acid. After a short time fine yellow crystals are precipitated. The mixture is kept boiling for some time, filtered by suction while hot and the residue washed with glacial acetic acid and water and dried. The new compound may be separated from its solution in sulphuric acid by the addition of small amounts of water in the form of a red-brown sulphate which crystallizes in needles. It conforms in its properties with that of Example 1.

Example 3 30 parts of 4'amino-2-phenylanthraquinone are suspended in a finely divided form in 1200 parts of water and treated at from to C. with 500 parts of sodium hypochlorite solution containing about 10 per cent of active chlorine. After some time the substance, which is then redyellow, is filtered oil? by suction, dried and, after purification corresponding to that in Example 1 or 2, a compound is obtained which is identical with those of the said examples in its properties.

Example 4 A solution of 1.5 parts of chromic acid in 1 part of water is added to a solution of 3 parts of 4'- amino-2-phenyl-5.8.dichloranthraquinone in 1500 parts of hot glacial acetic acid. The deposited of hypochlorite is detectable.

formed is filtered. off by suction, washed until red-yellow substance is filtered 011' by suction while hot and washed with glacial acetic acid and water. By crystallization from a large amount of nitrobenzene yellow crystals are obtained which dye cotton yellow shades from a yellow-red vat 5 and which dissolve in sulphuric acid giving a bluish red coloration.

Example 5 A sodium hypochlorite solution containing 10 about 10 per cent of active chlorine is allowed to drop into a suspension of 30 parts of finely dispersed 4'-amino-2.G-diphenylanthraquinone (obtainable from 4-phenylphthalic anhydride and 4- acetaminodiphenyl according to Friedel-Crafts, 5 ring closure to the anthraquinone derivative and saponification; red needles; the coloration of the solution in strong sulphuric acid is yellow-red) in 1200 parts of water at 60-70 C., until an excess The compound 20 neutral and recrystallized from nitrobenzene, if desired. The new compound is a diphenyl derivative of the azo compound described in Example 1. It dissolves in strong sulphuric acid with a 35 bluish red, coloration and dyes cotton powerful yellow shades from a yellow-red vat.

Example 6 A solution of 5.5 parts of potassium permanganate inparts of water is allowed to drop into a suspension of 15 parts of 4-amino-2-phenylanthraquinonejin 500 parts of water while stirring vigorously. When' all permanganate is used up, the pyrolusite thus formed isdissolved with sulphurous acid and the remaining red-yellow substance is filtered off by suctionand dried. It is recrystallized from nitrobenzene and is identical with the end product obtained according to the manner described in Example 1.

Example 7 30 parts of the amino-l-phenylanthraquinone (obtainable by nitration of l-phenylanthraquinone and reduction with sodium sulphide; bluish red crystals; coloration of the solution in strong 15 sulphuric acid is red-yellow) are dissolved in 1200 parts of boiling glacialacetic acid. Then a solution of 14 parts of chromic acid in 14 parts of water and 28 parts of glacial acetic acid is allowed to drop into the mixture. The brown compound thus formed isfiltered off by suction, washed with glacial acetic acid and then with water and dried. Bycarefully adding water, the compound may be separated from its solution in sulphuric acid in the form of its red-brown, well crystallized sulphate. It dyes cotton from a yellow-red vat reddish yellow shades.

Example 8 Example 9 12 parts of 4-amino-4'-beta-anthraquinonyldiphenyl (obtainable for example from 4-acetaminoterphenyl and phthalic anhydride accord- 7 acid, I I

there is introduced 1 part of dianthraquinonyl- 2,186389 ing tdFriedeFCrafts, ring closure to the anthraquinone derivative and saponification with sul .phuric acid; yellow-red crystals; coloration-of the solution in strong sulphuric acid is red-yellow) are dissolved in 120 parts of 96 per cent sulphuric acid. The solution is poured onto ice water, the precipitate filtered off by suction, washed until neutral, suspended in 1000 parts of water and treated at from to C. with 200 parts of sodium hypochlorite' solution. The coloration changes from currant to. reddish yellow. The new compound is separated in the usual manner and, if desired, purified by recrystallization from nitroben'zene or over its sulphate. It dis- I solves in sulphuric acid with blue-red coloration an'ddyes cotton from a yellow-red vat powerful I yellow shades. I

, I I Example 10 ,5 parts of 4'-amino-2-phenyl-6 ,(or 7-) -chloranthraquinone (obtainable from 4-chlorphthalic anhydride and 4-acetaminodiphenyl by a Friedel- Crafts synthesis, ring closure to the anthraquiinone derivative and saponification with sulphuric acid; bluishred crystals; coloration of the solution in strong sulphuric acid is yellow-red) are treated in aqueous suspension with parts of sodium hypochlorite solution at from 60 to 70 C.

The'brown-yellow compound thus formed may further'be purified, if desired, by recrystallization from nitrobenzene. Cotton is dyed yellow shades from a yellow-red vat. n p I Example 11 A sodium hypochlorite solution containing 10 per cent of active chlorine is allowed to drop at 60 C. into a. suspension of 20 parts of 4'-amino- '2-phenyl-5.6 (N) 7 (or -'7 (N) .8-) -pyridinoanthra- 'quinone (obtainable for example from quinoline- 5.6-dicarboxylic acid anhydride, melting point at from 185' to' 186 C.) and 4acetaminodiphenyl by a Friedel-Craftssynthesis, ring closure to the anthraquinone derivative and saponification; brown-red crystals; coloration of the solution in strong sulphuric acid is greenish yellow, coloration of the vat bluish red) in 1000 parts of water,

until an excess of hypochlorite is detectable and the brown-red compound changes to yellow-red. It is filtered off by suction, washed until neutral and recrystallized, if desired,from dichlorbenzene. The new compound dissolves in concentrated sulphuric acid giving a strong blue-red coloration. According to analysis and properties it is the azo compound corresponding to the amino compound employed. It dyes cotton from a-bluish red vat powerful golden-yellow shades.

Example 12 5 parts of a 50 per cent aqueous chromic acid solution are added to 50 parts of glacial acetic the whole is"heated to gentle boiling and hydrazobenzene of the formula I i (obtainable for example from thecorresponding dianthraquinonyl-azobenzene bytreatment with phenylhydrazine atfrom 140 to 150 0.; large deep brown needles which dissolve in sulphuric acid giving a brownred; coloration). The whole thraquinone.

is heated. .to boiling. until the i color of the initial .material haschariged to yellow without appreciable'amounts ofthe same being dissolved and a sampleof the filtered off "precipitate. dissolves 1 in sulphuric. acid giving: a blue-red coloration.

The whole is then filtered bysuctionand washed with water. A yellowcrystal powder is thus obtained having the properties'of the azo compound describedin Example 1. I

1 ,io a r tsgbr the in-itialrnatrial used. rungs ample ,12- are he'ated in250. parts' of anhydrous commercial pyridine at from about to-f? ,0. While the brown crystalswofftheinitial-material are still passing intosolution, small yellow needles already begin to separate. As-soon as initial material can no longer, be detected by with the azo dyes'tufi described in Example 1'. i

From the pyridine mother liquor, thereseparate uponstahding small brownish crystals which i consist' substantially of 4'-,amino-2-phenylanv Example 14 I '10 partsof 4-nitro-2phenylanthraquinone in a finely divided form are made into a paste with 500 parts of water; a solution of 1'7 parts of stannous chloride in 170-parts of 35 percent caustic soda solution is allowed to flow into the same at 20 C. while stirring; The temperature rises slightly; the color changes from the original yellow to dirty. grey-brown to yellow-red. After stirring for several hours at from 20 to 25 C.,

microscopic investigation,-.the whole is filtered by suction while hot and the solventois removed from the .filtercake. inthe usual mannen' The final product thus obtainedlconforms in itsproperties the whole is filtered by suctio'n'and washed until neutral. The dyestufi' obtained is identical in its properties with that obtained according to Example 1. I Errample i5 v n 11 parts of 3'-nitro-2phenylanthraquinone (obtainable for example from 4 '-acetamino-2- phenylanthraquinone by nitration, saponification of the acetyl group and removal of theamino group) are suspended in a finely divided form in a solution of 8 parts' of crystallized sodium sulphide in 200 parts of 60 per cent caustic sodasolution and heated to 140 C. for '7 hours while stirring, whereby the original yellow particles become red-yellow. The whole is diluted with water, filtered bysuction, washed until neutral and dried. A dyestuff which crystallizes in pale yellow needles from aniline is obtained which dyes cotton pale yellow shades from a red vat.

(obtainable -irom 4-- acetaminodiphenyl and phthalic anhydride by the process of Friedel- Crafts; saponification and oxidation with sodium hypochlorite to the corresponding azo compound) 1 are dissolved in 10.0 parts of 5 per cent oleum and the solution is then heated for 3 hours at from 120 to C. After-cooling, the whole is poured onto ice, and the separatedred-yellow precipitate is filtered oif by suction, treated with'dilute ammonia, washed until neutral and dried. A dyestuif is obtained which dissolves in sulphuric acid giving a bluish red coloration and which conforms in all its properties with the dyestufi described in Example 1.

I Example 17 A solution of 10 parts of ferric chloride in 200 parts of 10 per cent sulphuric acid is added to a solution of 5 parts of the tetrasulphuric acid ester potassium salt described in Example 19 in 200 parts of water. By heating at from to C. there separates from the yellow-red reaction liquid a pale orange precipitate which, after no increase in the same can be observed, is filtered off by suction and washed'until neutral. The dyestufi obtained conforms in its properties with the dyestufi described in Example 1. Sodium nitrite, chromic acid salts or hydrogen peroxide may also be used as oxidizing agents instead 0 ferric chloride. 7

- Example 18 30 parts oi azophenylbenzoyldichlorbenzoic acid'of the following constitution e1 CODE 11000 01 if 30 I 00 I oo 01 V o (obtainable for example from 4-acetaminod'1- yellow-brown powder, colorationof the solution in strong sulphuric acid powerful blue-red) are heated with 600 parts of 5 per cent oleum for an hour at from to C. Then the mixture is poured onto ice, the precipitate is filtered off by suction, treated with dilute sodium hydroxide solution, washed until neutral and dried. The dyestufi thus obtained may be further purified by dissolving it in sulphuric acid and separating the sulphate. It corresponds in its properties to that described in Examples 4. and 8.

If instead of azophenylbenzoyldichlorbenzoic acid, azophenylbenzoylphenylbenzoic acid, (obtainable from l-acetaminodiphenyl and 4'-phenylphthalic anhydride by a Friedel-Crafts synthesis; saponification of the acetaminophenylbenzoylphenylbenzoic acid to the aminophenylbenzoylphenylbenzoic acid and oxidation with hypochlorite; yellow-brown powder; coloration of the solution in alkali is yellow) is employed, a compound is obtained which conforms in all its properties with that described in Example 5.

Example 19.

14 parts of the dyestufi obtainable according to Example 1 and 14 parts of copper mealare added to a mixture of 21 parts of chlorsulphonic acid and 200 parts of pyridine and the mixture is stirred for 5 hours at from 40 to 50 C., the dyestufi thuspassing into solution with a red-yellow coloration. By introducing the mixture into ice, the pyridine saltof the leuco sulphuric ester separates as an oil. It is dissolved by stirring with 1000 parts of water and 50 parts of 60 per cent caustic potash solution, the copper removed by filtration by suction and the potassium salt of the leuco ester is precipitated from the yellowred colored ester salt solution at 50 C. by the tained.

addition. of 300 parts of'potassium. chloride. .It forms beautiful yellow-red needles which are separated in the usual manner. It dyescotton pale yellow shades; bydevelopment with an oxidizing agent, brillant yellow dyeings of excellent fastness are obtained.

Example 20 18 parts of chlorsulphonic acid are allowed toe drop into parts of drypyridine and into this mixture there is introduced at 40 C. a mixtureof 9 parts of the dyestufiobtainable according to Example 1. and 15 parts of, copper meal. After from 4 to 5 hours, all the dyestuif has passed into solution. The esterificatio'n mixture is introduced into ice-water, the separated oily pyridine salt is dissolved in a mixture of 50 parts of 60 per cent caustic potash solution. and 300' parts of water, copper is removed by filtration by suction and air is led at 40 C. into the resulting blackish red solution until its color has changed to a brilliant yellow-red. 125 parts of potassium choride are then added, while stirring, whereby the ester salt is deposited as beautiful red-yellow needles.

It conforms in its properties with the ester salt obtained according to Example 19.

Example 21' 20 parts of azo-l-phenylanthraquinone (ob- .tainable according to Example '7) and 30 parts of copper meal are'added to a mixture of 27 parts of chlorsulphonic acid and 400 parts of pyridine and stirred at40 C.,until the dyestuff has passed into solution. By adding the. mixture to 1200 parts of ice water, a viscous oil precipitates, which may be dissolved in 500 parts of 5 per cent potassium hydroxide solution. It is freed from copper by filtration, air is led for a short time through the red-brown liquid ..and theleuco sulphuric ester formed is salted out from the yelloW- red solution by adding 20 parts of potassium chloride in the form of its diflicultly soluble potassium salt. It dyes cotton yellow shades by developing the dyeing in the usual manner with acid and sodium nitrite.

Example 22 19 parts of chlorsulphonic acid are allowed to drop into- 300 parts of dry pyridine. Then a mixture of none (obtainable according to Example 4 or 8) and 14 parts of copper meal is added at 40 C. When all of the dyestuifhas dissolved, the whole is poured into 1000 parts of ice water, the separated oily pyridine salt of the leuco sulphuric ester is dissolved in 500 parts of 5 per cent potassium hydroxide solution, filtered oil from copper and, by adding 300 parts of potassium chloride, the ester is separated from the red-yellow filtrate.

By developing the dyeing in an acid bath with sodium nitrite, brilliant yellow shades are ob- Example 23 10 parts of thedyestuff/obtaihable according to Example 9, and 10 parts of copper meal are added to a mixtureof 14 parts of chlorsulphonic acid and 300 parts of pyridine and stirred at 40 C., whereby the dyestuii; slowly dissolves. Then the mixture is poured into ice water, the precipi- 4-aZo-2-phenyl-5.S-dichloranthraqui- I teed pyridine salt of the leuco sulphuric acid ester is treated with 400 parts of 5 per cent potas- I Example 24 V 30 parts of the potassium salt of the leuco' sula phuric ester of 4-acetamino 2-phenylanthraquinone (obtainable from 4-acetamino-2- phenylanthraquinone by treatment with copper;

powder and chlorsulphonic acid in pyridine) are dissolved in 300 parts of 3 per cent caustic potash solution; the solution is heated at from 80 to 90 C. for some time to saponify the acetylarnino,

group. After cooling, a sodium hypochlorite solution having about 10 per cent of active chlorine,-

is dropped in while stirring until potassium iodide starch paper becomes blue.

beautiful red-yellow needles separate. They are filtered off after some hours and wash'edwith potassium hydroxide solution. The leuco -sul-" phuric'acid. ester thus obtained conforms in its" properties with the leuco sulphuric acid ester describedin Example19. f

- Example 25 30 parts of the leuco sulphuric acid ester o-f 4'-nitro-2-phenylanthraquinone -(ob-tainab=le for.

example from 4' nitro-Z-phenylanthraquinone by treatment with copper powder and chlorsulphonic acid in pyridine) are dissolved in 1009 parts of 5 per cent caustic potash solution. and

an alkaline solution of stannous chloride is added until the color changes to brilliant red. Small amounts of precipitate arefiltered or and partspof potassium chloride are added at 50- 0.

whereby beautiful red-yellow needles separate which are entirely identical in properties to the obtained accordleuco-tetrasulphuric acid ester ing to Example 19. l

Example 26 v For the purpose ofdissolving 10 parts of the v potassium salt of the leuco tetra-sulphuric acid ester of dianthraquinonylhydrazo-benzene of the formula poses]:

red-yellow needles separate which conform completely in their properties with the leuco tetrasulphuric acid ester described'in Example 19.

Hydrogen peroxide or alkaline ferricyanid'es may also be used instead of hypochlorite solution.

uid is heated for a' short time at from 40to 50 C.,Whereby the leuco sulphuric ester of 4'-azofi-phenylanthraquinone is formed. It is sepa identical "in its properties with that obtained ac- The origmallyred- I yellow liquid is then deep red. It is heated to 60 1 C. andv pctassium chloride is added whereby j as claimed in claim 4.

'parts of .water is added to a solution of 30 parts of the. potassium salt of the leuco'sulphuric acid 5V I ester of 4-amino-2-phenylanthraquinone in 1500 parts of water. The mixture is then acidified with acetic acid while cooling with ice. The.

diazo compound of the leuco sulphuric ester of i.-amino -2 phenylanthraquinone thus obtained 6 is then allowed to flow into-280 parts of a solution of cuprous oxide in ammonia (prepared-from 35 parts of crystallized copper sulphate (cf. Liebigs Annalen, vol. 320, page 123)). The liqrated. according" to the manner described in Examples 24 to 26 with potassium chloride and. is v cording to Example 19. v v 20 If instead of the leucosulphuric ester of 4- amino-Z-phenylanthraquihone the leuco sulphuric ester. of the 1-amino-2.G-diphehylanthra-' quinoneKcf. Example 5) is used, a diphenylderivative of the leuco sulphuric. ester described in; Examples 19 and 20 is obtained.

If employing the leuco s'udphuric ester of 4- amino-2-phenyl-5.B-dichloranthraquinone. (yellowered aqueous solution) an esteris obtained which conforms in its properties With theleuc sulphuric ester of Example 22. a I

I What we claim is:

1. A vat dyestufi of thegeneral formula A-arN=N-ar'A in' which As stand for the same anthraquinonyl radicles and ar foran arylene radicle having from one to two non-condensed rings. 2. A vat dyestufi of the general formula in-which As stand for the'sameanthraquinonyl 4. Li'he vat dyestufi or o 1 9- o v q o 5. A leuco sulphuric ester of a vat dyestufi as claimed in claim 1.

6. A leuco sulphuric ester of a vat dyestufffas claimed in claim 2.

i :7. The'leuco sulphuric ester of the vat dyestufi as claimed in claim 3.

'8. The leuco sulphuric ester of the vat dyestuff p 70 HEINRICH 'NERESI-IEIMER. ERNST HONOLD. 1 BERTI-IOLD STEIN; MAXSCHUBERT.

' sinner ANTON, 15 

